Electrical system



Oct 16, 1934. E A ES 1,977,536

' ELECTRICAL SYSTEM Filed Nov. 25. 1932 T 6 I 3 2 I 65? PI .6). kl'fq 62 7 GB EB PB INVENTOR Efi ysf 753m Patented Oct. 16, 1934 v I I v UNITED STATES PATENT OFFICE 1,917.5 ELECTRICAL SYSTEM Ernest A. Tubbs, Long Island City, N. Y. Application November 25, 1932, Serial No. 644,249 11 Claims. (or. 179-111) This invention relates to electrical systems, energized by potential source 3 t assure faithand particularly to those electrical systems inful repeater effect, or amplified repeater eifect volving the conversion or translation of electrical if it be present, by the action of tube V on the energy eilects from one form to another. incoming oscillations.

An object of my invention is to translate from The modulating oscillating energy is introone form to another certain of the electrical duced from its source through transformer T2 effects generally essential to electrical communonto outer grid G2. This outer'grid is mainication practices. tained negatively energized by the source of po-' Examples of the conversion and translation retential SB, preferably to such a degree that the 0 sults contemplated by meare modulation to maximum positive operating potentials develproduce so-called modulated carrier currents; oped on outer grid G2 by the modulating oscildetection to extract signal representing effects lations will not completely overcome the negative from modulated carrier currents; and heterostatus originally established. In other words, dyning different frequency electrical oscillations the adjustment should preferably be such that I to produce a third or beat oscillation. outer grid G2 never draws current from the u t er bj d the features of my n" Space discharge path in following the variations vention will be understood by reference to the of potential thereon imposed by the impressed figures of the drawing in connection with the modulating oscillations. following description thereof, like reference It is generally appreciated by the art that the characters representing like parts in the sevbiasing potential on an electrode located to eferal figures so far as permissible. fectively influence current flow in a space dis- Figures 2 and constituting the drawing, charge path can belso chosen that the variations diagrammatically illustrate diiferent emboditherefrom within practical limits produce modiments of my present invention, the choice of a fications in the space current flow which are 5 Particular embodiment dependin upon considquite efiectively substantially linearly proporerations hereinafter particularized. tional to the magnitudes of the variations, this Various circuits of the systems of the several being generally viewed as working on the linear figures include by conventional showing enerportion of the so-called characteristic output gizing sources of potential, such as the batteries curve of such devices. Expressed in another conventionally indicated by alternate long and way, it may be said to be possible to so initially ShOlt lines, and using the short line side of the adjust the energizing of a space discharge inconventional showing to represent or indicate fiuencing element that variations within limits the negative sides Of the various potential. on each side of the setting will not materially sources throughout the systems of the several alter the mutual conductance or amplification 35 figures is followed throughout. In other words, factor of the device. the polarities of energizing at one place or an- Prior developed practices for modulation of other in the several embodiments are readily one electrical oscillation by another electrical determined y in p i n of the figures- F r oscillation with the aid of electronic repeaters example, noting in Fig. 1 the connection of grid or repeating amplifiers usually involve bringing G1 of tube V to an indicated point of positive the interacting oscillations into contact through potential in plate battery PB establishes that circuits with parts thereof so much in common grid G1 is positively energized, but less positively or so closely associated as to make quite difllenergized' than anode P. cult design of satisfactory arrangements for ac- Fig. 1 illustrates an arrangement capable of commodating the different contributing oscilla- 45 effective modulation of an electrical oscillation tions.

by a second electrical oscillation. An electron Referring to Fig. 1, it is seen that in my artube V of the well-known pentode form for exrangement the oscillations to be modulated and ample, including usual heated cathode F, inner the modulating oscillations are impressed upon or control grid G, screen grid G1, outer or soappropriate electrostatically isolated elements 0 called suppressor grid G2, and anode P, is conof tube V through wholly independent, non-re- 105 nected to receive onits control grid G the elecactively isolated circuits, and that the resulting trical oscillations intended to be modulated, this modulated oscillations depart from-the region from a suitable source connected to supply these of contact so established by way of the wholly oscillations through transformer T1 as shown. independent output circuit leading to output The grid G'of tube V is selectively negatively transformers T3 from anode P of tube -V. Re- 1.10

fen-ing to Fig. 1, it is seen that the screen grid G1, interposed between inner grid G and outer grid G2, positively energized as it is by battery PB, effectively electrostatically isolates the inner and outer grids from each other.

The arrangement also provides for independent selection of the potential of potential source GB for properly biasing control grid G for best repetition or amplifying repetition of the oscillations to be modulated, and for independent selection of the potential of potential source SE for properly biasing outer grid G2 for assured faithful modulation results.

Sources of potential F13 and PB provide for energizing the cathode, screengrid and anode of tube V respectively normal manner for causing the tubes to function as intended.

The system of Fig. 2 functions to erase from the output or resultant oscillations certain of the characteristics of the source or initial oscillations. Two like pentode tubes V and V', constituted and energized as described for tube V in Fig. 1, are connected as shown, which is in accordance with well understood practice.

It is apparent that with the arrangement so adjusted that equal but oppositely acting potentials of an oscillation incoming through transformer T1 are applied to control grids G and G of like acting tubes V and V, the resulting output oscillations will pass through the primary winding of transformer T3, common to the two circuits, in opposing fashion, and there will be no fundamental oscillating energy induced into the work circuit connected across the secondary of transformer T3.

Likewise, if equal and oppositely acting potentials of an oscillation incoming through transformer T2 are applied to outer grids G2 and G'2, no indication of the fundamental thereof will appear in the output work circuit.

The perfection of these results obviously depends upon how closely the two tubes are equivalent in their functioning, and how closely the paralleled circuits are balanced. In the case of unequal parallel operation for any reason, the degree of energy of unwanted characteristic that may pass over into the output work system depends upon the degree of acceptability of the output work system for the frequency of the escaping oscillation. In many usual practices the acceptability factor ortuning of the output work system is so far removed in periodicity from that of the possible unwanted but escaping oscillation energy as to make the matter of selection of tubes and balancing of the paralleled circuits of no serious practical consequence.

As to use that may be made of the capabilities of the system of Fig. 2, it is apparent that if oscillations of different characteristics are simultaneously applied to the system through input transformers T1 and T2, the output components of the oscillations will interact to assert their differences wherever the two oscillations may meet; They meet in the primary of output transformerT3, and there develop potential disturbances representative of their difierences, which disturbances are induced into the output work circuit. If the output system is tuned favorably to the periodicity of the manifested difference, it resonantly or more acceptably takes over. the oscillations to be used as oscillating electrical energy freed of the characteristics possessed originally-in the two separate sources.

For example, the operation may amount to simple heterodyning or beat frequency production. The oscillation introduced through transformer T1 may be of pure sine form of one high frequency and the oscillation introduced through transformer T2 also of pure sine form of another high frequency, with the result that an oscillation of pure sine form of frequency equal to the difference between the frequencies of the original oscillations, and free other than in amplitude from the characteristics thereof, appears in the output working system.

As another example, the T1 introduced oscillation may be of pure sine wave high frequency nature, and the T2 introduced oscillation of a range of varied low or audio frequency representative of voice, music or other varied sound. In this case the output oscillations through output transformers T3 will not be the original T1 oscillation .merely varied in amplitude in accordance with the varying T2 oscillation, but rather a series of so-called side band oscillations made up of heterodyne produced or beat frequency oscillations resulting from interactions between the original T1 oscillation and the various sound representing oscillations of the T2 oscillation.

The T2 oscillation, in the matter of its original frequency characteristic, is not present in the output result other than to the extent it uses lack of perfection in practical tube 'construction and circuit balance to evade its sought elimination.

The system of Fig. 2 may be used to function effectively as a so-called detector, being a complete demodulator of usual signal modulated oscillation. For example, if either an originally introduced T1 or T2 oscillation is but the usual modulated carrier current common to radio telephone and like interrupted continuous wave radio practice, the amplified carrier currents per se are extinguished at output transformer T3, but the signal representing modulations thereof effect output transformer T3 to manifest themselves for the physical reasons heretofore stated by Carson in his United States Patent 1,343,306 of June 15, 1920, commencing line 114, p e 2, to line 83, page 3 of the said patent.

Fig. 3 differs from Fig. 2 in having input transformer T2 connected to impress oscillating potentialson the outer grids G2 and G2 of tubes V and V' in step or symmetry rather than in the opposition fashion shown in Fig. 2. Obviously, this modification in the arrangement can be effected as well by leaving input T2 in Fig. 3 as it is in Fig. 2, and inverting input T1 in Fig. 3.

The result of this modification is that the one of the oscillations applied to both grids out of step acts in step in the push-pull type of output transformer T3 shown, and therefore is present in the output system along with the reactive or beat effects if the system is used in connection with oscillations simultaneously impressed on both input systems.

Fig. 3 also differs from Fig. 2 in the mode of connection of output transformer T3 into the system. In Fig. 2 the whole of the primary of output transformer T3 is connected to be common to. the output circuits of the two tubes, whereas in Fig. 3 the output transformer T3 is connected in so-called push-pull fashion, the primary winding being split by the output circuits of the two tubes as shown. The result is that if two or more oscillations of different frequencies, or modulated oscillations, are applied,

as may be necessary in some practices, to the same grids through either one of the inputs, the beat oscillations or detection oscillations thereof will not appear in the output oscillations of Fig. 3. In other words, the appearance of beats or other distortion oscillation eifects is only had as between oscillations applied todifferent pairs of grids.

While I have illustrated the use 01' two separate tubes in the systems of Figs. 2 and 3, it is, of course, appreciated that the same results and effects can be had by embodying the two controllable space discharge paths needed in a single tube, a construction not uncommon in tube production of today. Additionally, arrangements employing more control elements than usual to the pentode type of tube may be used.

While I have limited the description of my invention to only those adaptations thereof necessary to an understanding of the novel features embodied, no limitations are intended thereby beyond those imposed by the appended claims. Nothing herein is intended to waive any patentable features of my copending application for Letters Patent of the United States, Serial Number 737,948, filed August 1, 1934.

Having fully described my invention I claim:

1. In an electrical system the combination of a continuous electron discharge path comprising ,an electronemitting cathode and a posi- I tively energized anode, a plurality of negatively energized electrodes spaced between said cathode and anode,and electrostatically isolated from each other by an electrode interposed therebetween, a plurality of sources of oscillations, and means for impressing difierent ones of said oscillations upon different ones of said negatively energized electrodes, the negative energizing of a one of said electrodes between said interposed electrode and said anode being so proportioned that substantially no current is thereby drawn from said electron discharge path during operation, whereby fidelity of operation is enhanced.

2. In an electrical system the combination of a pair of like continuous electron discharge paths each comprising an electron emitting cathode, a positively energized anode and a pair of differently spaced interposed electrodes, said ,electrodes being electrostatically isolatedone from the other by an electrode interposed therebetween, two sources of oscillations, means for negatively energizing said interposed electrodes, connections for separately impressing the energies of said oscillations each on the like ones of the negatively energized interposed electrodes, and means for transferring the resulting oscillations imposed on the anodes of said paths.

3. In an electrical system, the combination of lan electronically active path comprising an electronemitting source and an appropriately spaced therefrom positively energized anode, diilferently spaced control electrodes interposed between said source and said anode, saidv control electrodes being electrostatically isolated one from the other by an electrode interposed therebetween, separate sources of electrical oscillations, separate means for impressing one of said oscillations between said electron emitting source and one of said control electrodes, separate means for impressing .another one of said oscillations between said electron emitting source and a control electrode farther removed therefrom, and means for so negatively polarizing said farther removed electrode that in operation substantially no current is thereby drawn fidelity of operation is enhanced.

from said electronically active path, whereby 4. In an electrical system, the combination of an electron discharge path comprising an electron emitting cathode and a cooperating posiaw tively energized anode, a pair of differently spaced grid electrodes interposed in said path, said grid electrodes being electrostatically isolated one from the other by an electrode inter-p posed therebetween, a pair of separate sources of electrical oscillations having separate connections for separately impressing them one between said cathode and the nearer thereto one of said grid electrodes, and the other between said cathode and the farther removed theretron emitting source and an appropriatelyspaced therefrom positively, energized anode, differently spaced electrodes interposed between 'said sourceand said anode, an electrode between two of said interposed electrodes positively energized to a lesser degree than said anode, separate sources ofelectrical oscillations, separate means for impressing one of said oscillations between said electron emitting'source and one of said interposed electrodes located between said source and said positively energized inter posed electrode, separate means for impressing another one of said oscillations between said electron emitting source and a control electrode on the far side of said positively energized interposed electrode, and means for so negatively polarizing said far side electrode that in operation substantially no current is thereby drawn from said electronically active path, whereby fidelity of operation is enhanced.

6. The method of modulating electrical alternating current in a thermionic tube having an electron emitting source, an anode and an electron stream space path therebetween, which comprises constantly attracting electrons of said stream to an intermediate position in said path,

negatively repelling electron movement at a position beyond said intermediate position, modulating the density of the attracted electrons by variably polarizing that part of said electron stream subjected to said constant attraction, further attracting electrons to said anode, and causing said alternating current to vary said negative repelling of electron movement less than enough on the positive half cycles of the alternating current to draw substantially no electrons from said electron movement, whereby the fidelity of modulation is enhanced.

'7. The method of modulating electrical alternating current in a thermionic tube having an electron emitting source, an anode and an electron stream space path therebetween, which comprises attracting electrons of said stream to an intermediate position in said path, negatively repelling electron movement at a position beyond said intermediate position, modulating the density of theattracted electrons by variably polarizing said stream at a position ahead of said intermediate position, further attracting electrons to said anode, and causing said alternating current to varysaid negative repelling of electron movement less than enough on the positive half cycles of the alternating current to draw substantially no electrons from said electron movement, whereby the fidelity of modulation is enhanced.

8. The method of modulating electrical a1- ternating current in an electronically active path having an electron emitting source, an anode and an electron stream space path therebetween, which comprises constantly attracting a substantial part of the electrons of said stream to an intermediate position in said path, modulating the density of said constantly attracted electrons, further attracting electrons to said anode, causing said alternating current to vary said further attraction, and sufliciently negatively polarizing the varying of said further attraction that substantially no electrons are drawn from said electron stream on the positive half cycles of the alternating current,

whereby the fidelity of modulation is enhanced.

9. The method of modulating electrical alternating current in an electronically active path having an electron emitting source, an anode and an electron stream space path therebetween, which comprises attracting electrons of said stream to an intermediate position in said path, modulating the density of the attracted electrons by variably polarizing said stream at a position in advance of said intermediate position, further attracting electrons to said anode. causing said alternating current to vary said :further attraction, and sufllciently negatively polarizing the varying of said further attraction that substantially no electrons are drawn from said electron stream on the positive halt cycles of the alternating current, whereby fidelity of modulation is enhanced.

10. In a system for modulating electrical alternating current, a thermionic tube comprising an electron emitting source, a pair 01' electrodes relatively close together, the said electrode nearer said electron emitting source being positively energized and the other one of said electrodes being negatively energized, a positively energized anode beyond said negatively energized electrode, a source of alternating current connected to said negatively energized electrode, an electrode interposed between said electron emitting source and said pair of electrodes, and a second source of alternating current connected to said last mentioned electrode, said negatively energized electrode being sufliciently .so energized that substantially no current is drawn thereby during the positive hali' cycle of the impressed thereon alternating current, whereby the fidelity of modulation is enhanced.

11. In a system for modulating electrical alternating current, a thermionic tube comprising an electron emitting source, a pair of negatively energized electrodes and an interposed therebetween positively energized electrode, a positively energized anode beyond said electrodes, and separate sources of alternating current connected to said negatively energized electrodes, the one of said electrodes nearer to said anode being sufilciently negatively energized that substantially no grid current is drawn thereby during operation, whereby fidelity of modulation is en- 

